Ballistic resistant panels can safeguard people and property from ballistic threats, such as projectiles. Ballistic resistant panels can be incorporated into vests to protect people from projectiles, such as bullets or shrapnel, and can be incorporated into vehicle doors and floors to prevent occupants and equipment from projectiles and blasts. Ballistic resistant panels are commonly made of woven fabrics consisting of high performance fibers, such as aramid fibers. When struck by a projectile, fibers in the woven fabric dissipate impact energy transferred from the projectile by stretching and breaking, thereby providing a certain level of ballistic protection.
Existing ballistic resistant panels are often made of a stack of woven ballistic sheets stitched together by a sewing process that requires an industrial sewing machine. The level of ballistic protection provided by the panel is largely dictated by the type of fibers in the woven ballistic sheets, the number of woven ballistic sheets in the stack, and the stitching pattern used to bind the woven ballistic sheets together into a panel. A wide variety of stitching patterns are used in existing panels, including quilt stitches, radial stitches, row stitches, and box stitches.
When a projectile strikes a panel made of a stack of woven ballistic sheets bound by stitching, each woven ballistic sheet dissipates a certain portion of the energy of the projectile as the projectile passes through each sheet. Within each woven ballistic sheet, individual fibers stretch and break apart as the projectile penetrates the sheet. The impact energy absorbed by a struck fiber will be transferred and dissipated to nearby fibers at crossover points where the fibers are interwoven. Also, individual stitches will stretch and break apart as the projectile enters the panel, thereby dissipating impact energy from the projectile and acting as a sacrificial element of the panel.
Due to the sacrificial nature of the fibers and stitches, the panel will be severely damaged when struck by a projectile. Visual inspection of the panel will typically reveal significant damage to the woven ballistic sheets and to stitches both at the impact location and the surrounding area. If a second projectile strikes the panel at or near the first impact location, the panel will not effectively stop the second projectile, and the second projectile will pass through the panel and into a person or property behind the panel. Therefore, existing panels do not provide reliable protection against multiple projectiles striking the panel in close proximity, which is a common threat posed by many automatic and semi-automatic weapons. For at least this reason, existing ballistic resistant panels are not well-suited for applications where multi-round capability is required.